Polynomial regression: Difference between revisions

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 =={{header|Go}}==
+===Library gonum/matrix===
+<lang go>package main
+import (
+    "fmt"
+    "github.com/gonum/matrix/mat64"
+)
+var (
+    x = []float64{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+    y = []float64{1, 6, 17, 34, 57, 86, 121, 162, 209, 262, 321}
+    degree = 2
+)
+func main() {
+    a := Vandermonde(x, 2)
+    b := mat64.NewDense(11, 1, y)
+    fmt.Printf("%.3f\n", mat64.Formatted(mat64.QR(a).Solve(b)))
+}
+func Vandermonde(a []float64, degree int) *mat64.Dense {
+    x := mat64.NewDense(len(a), degree+1, nil)
+    for i := range a {
+        for j, p := 0, 1.; j <= degree; j, p = j+1, p*a[i] {
+            x.Set(i, j, p)
+        }
+    }
+    return x
+}</lang>
+{{out}}
+<pre>
+⎡1.000⎤
+⎢2.000⎥
+⎣3.000⎦
+</pre>
+===Library go.matrix===
 Least squares solution using QR decomposition and package [http://github.com/skelterjohn/go.matrix go.matrix].
 <lang go>package main